Ladders are used on pitched roofs for many purposes, e.g. shingling, roof repair, chimney repair and the like. One particular use is ventilation during fire fighting. This is the systematic removal of smoke and heated fire gases from a burning structure. Ventilation is performed in four basic situations. These situations include fire control, fire attack, rescue and overhaul. Firefighters have a choice of basic ventilation types to accomplish the objectives of these situations. The basic types are vertical, horizontal, and forced ventilation.
Vertical ventilation is allowing heat and smoke to travel upwards and out of a structure. This is performed by cutting vents or making use of existing openings in the roof of the structure. To accomplish vertical ventilation requires many resources. At a minimum, these resources include two well-trained and fully protected firefighters, cutting equipment, ladders, and a charged water line. Once these resources have been assembled and moved to the roof, vertical ventilation normally involves first opening existing openings and then making roof cuts as close as safely possible to the seat of the fire. Firefighters making roof cuts know one large vent is more effective than several small vents and once vertical ventilation is completed, return immediately to the safety of the ground.
The advantage to vertical ventilation is found in basic fire behavior. Due to convection, the first choice of heat is to travel straight up. Vertical ventilation allows this natural movement to occur and is, consequently, the most effective form of ventilation. When vertical ventilation is properly performed, it can greatly reduce the mushrooming of gases and improve the conditions inside the structure. There are several disadvantages to vertical ventilation. First, firefighters are subjected to all the dangers of being on the roof of a structure. These include structural collapse, disorientation, and falls. Second, vertical ventilation takes time to perform and is often impractical. Many roofs are extremely difficult to breach and fires not on the top floor may see little benefit to the operation. Third, as described above, vertical ventilation demands many resources. Most departments do not initially have the firefighters necessary to perform vertical ventilation in the early stages of an incident. Even though these disadvantages exist, sometimes, vertical ventilation is preferred.
When fire departments have adequate personnel, vertical ventilation and other operations can be performed simultaneously. Departments that do not have these resources must still recognize when vertical ventilation can assist the operation. Of the four situations discussed, fire control is most accomplished with vertical ventilation. Fire attack, rescue, and overhaul have other ventilation options that departments with limited personnel can perform. The objective of fire control is to stop the horizontal spread of the fire and vertical ventilation makes this possible. This is especially true with attic fires and fires in balloon construction.
Although it will often be too dangerous to vent an attic fire, fires in balloon construction can benefit from early vertical ventilation. Fires that have penetrated into the walls of such structures will quickly travel to the attic. From there, the fire will rapidly spread throughout the structure. If vertical vents have been placed early, before the fire has weakened the roof, the effects of fire spread will be reduced.
The device of this invention is a ladder accessory that is easily attached to a roof ladder that provides additional footing support thus making the creation of vertical ventilation easier and safer. The invention is used in aiding firefighters to cut holes in the roofs of burning buildings to provide ventilation as described hereinbefore. In conventional firefighting procedure, where the roof of a building is exposed to the fire, it is necessary to open a hole in the roof so the smoke and flame will be concentrated there rather than weakening the entire roof. This also creates an updraft that has a tendency to clear the windows and doors of smoke so the firefighter may evacuate persons trapped in the building and they may enter the building to fight the fire.
In making such an opening it has been the practice to use a single roof ladder hooked over the ridge of the roof. The firefighter must then lean over and chop or cut a hole near the side of the ladder. This is a very awkward and dangerous procedure. He may have to leave one foot on the ladder and put one foot on the roof. Sometimes the fire fighter will drive the pick end of his axe into the roof to provide a support for one of his feet. This is unsafe and the fire fighter may need his axe.
In another technique the firefighter may be assisted by a second fire fighter who uses a Halligan/Trash tool or hook to enable the fighter cutting the hole to brace one of his feet. These tools need to be embedded into the roof while the present invention does not. As an improvement to this method the apparatus of U.S. Pat. No. 4,901,818 has been suggested. However this requires using two ladders and a large cumbersome platform suspended between the two ladders. Often there is not sufficient room to place two ladders, or not a sufficient number of firemen to place the ladders and the platform.
By a unique and simple design the ladder step accessory of the present invention may be used with a conventional ladder to form a safe support for the second foot of the fireman. The invention improves cutting a hole in the roof. The versatility of the present invention also makes it useful for combating chimney fires, fire rescue out of dormer windows, marking roof edge during dark and or under smoky conditions thus preventing slipping off of a roof, as a tool catch to prevent tools from sliding off a roof, operations platform for working on fascia and soffits and the like. The device may also be used for other roof maintenance projects such as repairs, shingling, chimney work and the like.
Several devices have been suggested which support either a step or a scaffold from one or more ladders. U.S. Pat. No. 4,279,327 (Warren) and U.S. Pat. No. 4,531,613 (Keigher) are two patents that relate to firefighting but show a single ladder has an extension at the top that is wide enough to embrace the area where the hole is made. These two patents show devices that limit the firefighter to the area where the ladder has been hooked and place him/her directly over the cut to be made in the roof Moreover they are cumbersome and require the attachment be made a part of the ladder. This then requires additional large equipment to be carried by the fire truck. In U.S. Design Pat. No. 365,156 a foot holder is suggested that requires using a pin to attach an arm that is not braced. This can be a very cumbersome and difficult for a fireman to attach to a ladder.
None of the art provides a ladder accessory that can also be carried on the ladder rungs in a vertical position parallel to the ladder rails that adds further convenience and safety for workers. This also reduces the need for additional manpower. For example FIG. 8 of U.S. Pat. No. 5,099,952 shows the need for a worker to carry the device illustrated there slung over his shoulder. This is cumbersome especially if the worker also needs to carry other tools.